The present invention relates to a device for heat-insulated diving suits for underwater work at great depths, and including a helmet, which is connected to a breathing apparatus with a mainly closed respiration circuit.
Routinely, at the present time, divers are used in connection with work under water down to approximately 200 meters. There is a desire to enable work at even greater depths, e.g. down to about 450 meters, but at these depths, among a lot of other things, the great pressure leads to a result that the breathing gas becomes inert to breath, it also takes a large amount of heat to heat the gas if it is cold. The gas consumption increases and it is essential that the input gas partial pressure be kept within close ranges.
To overcome these problems, different ways to regulate the oxygen partial pressure in the breathing circuit have been suggested, whereby the diver, through conduits, is connected to an observation chamber or the like, where a measuring device continuously measures the partial pressure of the oxygen and, independent of this measuring, supplies a oxygen-rich gas compound to the diver's breathing circuit. The system requires a relatively complicated oxygen sensitive electronic equipment, which must function under normal pressure- and humidity conditions and it therefor can not be included in the diver's own personal equipment.
Present-day breathing systems are often so-called open systems of "demand"-type, in which the already-prepared gas is inhaled thereupon to be exhaled, directly into the water. In order to save gas when diving at great depths, the so called "reclaim system" is also used, in which exhaled gas is collected, which is sucked, or, due to the pressure difference flows, to a diving-bell or to a vessel on the surface, where it is purified and then pumped back to the diver. Such a system, with its pumps and hoses, becomes both space and energy demanding, as it has no natural, built-in emergency system, if the "umbilical cord" should break. A gas bottle on the back of the diver connected to this system gives emergency breathing time of only about 30 seconds down at 450 meters depth, which is quite insufficient.
Through U.S. Pat. No. 3,345,641 there is earlier known a ventilated space suit, having on the outside a portable breathing apparatus which includes a closed respiration system, in which oxgenized air is allowed to circulate within the entire space suit, for transporting humidity from the body to a dehumidifier provided outside the suit. Through the respiration system, in which the gas is purified remove carbon dioxide, in an absorber, much better gas economy can be achieved via considerably simplier techniques than earlier known systems, but a breathing equipment for a space suit works under completely other conditions than corresponding equipment for a diving suit, since the pressure at a water depth of 450 meters is about 100 times as large as the pressure maintained in a space suit.
To prevent the diver from freezing to death, it has become essential, that, beside an active heating of the suit, also there is provided a heathing of the breathing gas, when diving down to depths below 150-200 meters. Upon the occurrence of an interruption on the "umbilical core", when also the energy supply is shut off, the diver rapidly becomes frozen stiff if an efficient emergency system can not be turned on.